ISRO's SpaDeX Mission Achieves Successful Second Satellite Docking

Union Minister Dr. Jitendra Singh announced the successful completion of the second satellite docking under ISRO’s SpaDEX mission on Monday. Sharing the update on social media platform X, the minister expressed satisfaction over the achievement, stating, “Glad to inform that the second docking of satellites has been accomplished successfully.”

Timeline of SpaDEX Milestones

Dr. Singh highlighted the progress of the Space Docking Experiment (SpaDEX) mission, which began with the launch of the PSLV-C60 rocket on December 30, 2024, from the Satish Dhawan Space Centre in Sriharikota. The first successful docking operation took place on January 16, 2025, at 6:20 AM, followed by an undocking event on March 13, 2025, at 9:20 AM.

The latest docking marks another critical milestone in India’s push to master autonomous orbital operations.

India Joins Elite Club of Space Docking Nations

India has now become the fourth country in the world to demonstrate satellite docking capabilities in space. The successful SpaDEX docking places ISRO alongside global space leaders—the United States, Russia, and China—in possessing this advanced spaceflight technology.

This technological feat signals India’s growing competence in handling complex in-orbit maneuvers and strengthens the nation's long-term goals in human spaceflight and satellite servicing.

Technical Overview of SpaDEX Mission

The SpaDEX mission (Space Docking Experiment) involved two mini-satellites, each weighing approximately 220 kilograms. These were named:

• SDX01 (Chaser satellite)

• SDX02 (Target satellite)

Launched together aboard the PSLV-C60, the satellites were designed to carry out autonomous docking procedures in low Earth orbit.

Bharatiya Docking System: Indigenous Docking Technology

At the heart of the SpaDEX mission lies the Bharatiya Docking System (BDS) — ISRO’s indigenously developed docking mechanism. This system comprises:

• A robust docking mechanism

• Four rendezvous and docking (RVD) sensors

• Power transfer interfaces

• An Inter-Satellite Link (ISL) for communication

• An autonomous docking strategy with embedded artificial intelligence

The BDS allows each satellite to detect, analyze, and respond to the state of its partner satellite during docking operations—enabling truly autonomous space maneuvering.

More Experiments Ahead in the Coming Weeks

Dr. Singh also stated that more space-based experiments are scheduled over the next two weeks. These are expected to test the limits of India’s orbital docking systems further, providing valuable data for ISRO’s upcoming human spaceflight and deep-space missions.

Strategic Significance of SpaDEX Technology

According to ISRO, SpaDEX is a critical stepping stone for India’s aspirations in:

• Human spaceflight programs like Gaganyaan

• In-orbit satellite servicing and refueling

• Modular space station construction

• Future lunar missions like Chandrayaan-4

• Deep-space exploration without relying on Earth-based navigation systems such as GNSS

Mastering autonomous docking will allow India to reduce dependence on foreign technologies and ensure greater mission flexibility and independence in space.

Conclusion

The successful completion of the second satellite docking under ISRO’s SpaDEX mission marks a major technological milestone for India’s space program. By joining the elite group of nations capable of autonomous satellite docking, India has not only showcased its engineering excellence but also laid a strong foundation for future space endeavors such as human missions, in-orbit servicing, and space station development. With the Bharatiya Docking System proving its capability, ISRO has taken a decisive step towards self-reliance in critical space technologies and advancing its position as a key global player in the new space era.